Airports

Group Delta, an NV5 Company, performed a geotechnical investigation, provided design recommendations, and construction inspection services for this 14.5-acres site that includes two-story FBO terminal building, four new hangers and offices, and parking, taxi-lanes and ramps.

Our team utilized a limited access drill rig and Cone Penetration Testing (CPTs) for the investigation that allowed for minimum mast heights to avoid the need for FAA permits as typically required for a standard truck-mounted drill rig. The subsurface investigation identified a loose sandy layers within the upper 10 feet that required remedial grading for adequate bearing at large column loads and one at depth that was prone to liquefaction and associated liquefaction-induced settlements.

Deep foundations were avoided by proposing options for remedial grading to allow shallow foundations. Remedial grading options included ground improvement with GeoPiers (rammed aggregate piers) or removal of 10 feet of soil and backfill with compacted onsite materials or aggregate base was allowed if a larger modulus below large hanger column loads was required to minimize settlements. Pavement design was completed utilizing both Caltrans Highway Design Manual and Federal Aviation Administration Design Methods.

 Added Value

• Innovative Drilling Approach: Our team utilized limited access drill rigs and Cone Penetration Testing (CPTs) to avoid FAA permit requirements, streamlining the investigation process.
• Cost-Effective Foundation Design: Our team identified subsurface risks and proposed remedial grading options—such as GeoPiers or soil replacement—to eliminate the need for deep foundations.
• Aviation-Grade Pavement Design: Our team delivered pavement recommendations using both Caltrans and FAA design methods to meet the diverse demands of taxi-lanes, ramps, and parking areas.